58 THE REPORT OF THE No. 33 



The Spring Canker Worm (Paleacrita vernata). Many neglected apple 

 orchards in the Province were completely or almost completely defoliated by 

 this species. • Reports of severe damage were received from Welland, Went- 

 worth, Peel, Northumberland and Durham Counties, and no doubt the insect 

 occurred in injurious numbers in other parts of the Province. Elms as well as 

 apple trees were stripped — one elm grove of about 2,000 trees near Brampton 

 lost nearly every leaf. This particular grove, according to residents of the 

 district, has been defoliated three years in succession, and it is feared that further 

 injury will result in the death of a number of the trees. 



The Yellow Tussock Caterpillar (Halisidota tesselaris). In late sum- 

 mer and fall this insect was present in immense numbers in southwestern Ontario. 

 The caterpillars attacked various trees and shrubs, but the main injury was 

 done to apples, whole orchards being defoliated in several instances, e.g., at 

 Dixie, North Toronto, Oshawa, Owen Sound and Elmira. The caterpillars 

 began to appear in August, and in early September trees were stripped as a 

 result of their feeding activities. 



This is the first time in our experience that Halisidota tesselaris has been 

 sufficiently abundant to cause much injury. 



San Jose Scale (Aspidiotus perniciosus). This pest is still increasing in 

 the warmer sections of the Province, and requires better attention in many 

 orchards than it has been given in recent years. In parts of Elgin County, 

 parasites appear to have had a marked effect in checking the San Jose scale. 



The Apple Maggot (Rhagoletis pomonella). Reports of injury from this 

 pest were received from several localities. We are glad to say that wherever 

 (except under village or town conditions) a real effort has been made to combat 

 the maggot, no difficulty has been experienced in bringing it under control. 



Apple Aphids. The green apple aphis {Aphis pomi) appeared in outbreak 

 form about midsummer in several localities in southwestern Ontario. On 

 badly attacked trees the wood, leaves and fruit became literally covered with 

 honey-dew, and with the black honey-dew fungus. During September the 

 insect largely disappeared, and heavy rains cleaned the apples in most orchards. 

 However, at a few places the aphis was abundant to the close of the season, and 

 much of the fruit was badly smutted with the honey-dew fungus. It is of 

 interest to note that in one orchard, consisting of alternate rows of Mcintosh 

 and Fameuse, the former was only slightly infested, whereas the latter was 

 badly attacked. 



The rosy apple aphis (Anut -aphis rosens) was responsible for considerable 

 injury in a few orchards in the Niagara district, but, generally speaking, this 

 species was of little importance. 



Cigar and Pistol Case Bearers (Coleophora fletcherella and C. malivorella) . 

 These insects were abundant in apple orchards east of Toronto, especially 

 in the Bowmanville-Newcastle district, where the severe outbreak of case 

 bearers occurred in 1921. Elsewhere they were of no importance. 



The Apple Tent-Caterpillar (Malacosoma americana). In most parts 

 of the Province this insect was scarce, but around Morrisburg numerous webs 

 were found oil trees along the roadside, indicating that possibly another out- 

 break will occur in eastern Ontario in a few years. 



